Drinking water, infrastructure needs fixing before residents can return to flood-hit NT communities, authorities say

https://www.abc.net.au/news/2023-03-15/nt-evacuees-unable-to-return-kalkarindji-daguragu-pigeonhole/102094532  15 March 23.

Evacuees from flood-hit Northern Territory remote communities are not yet allowed to return to their homes, with authorities citing badly damaged infrastructure and a lack of safe drinking water.

The communities of Kalkarindji, Daguragu and Pigeon Hole were all inundated by fast-rising floodwaters after the Victoria River broke its banks late last month.

Hundreds of residents were evacuated by air and have been housed for up to a fortnight at Darwin’s former COVID quarantine centre in Howard Springs.

Deputy Chief Minister Nicole Manison said there remains “a very big job ahead” and declined to estimate how long it might be before people can start returning home.

“We are going through those plans about how we can get people back into their homes safely [and] as quickly as possible,” Ms Manison said.

“We are deeply concerned about the level of damage to some of those places.”

She said repairs are needed to critical infrastructure and safe drinking water is yet to be confirmed in Daguragu and Pigeon Hole.

Photos of the communities supplied by government officials show thick, dried mud caking the floors of houses, football grandstands littered with debris and a local schoolroom trashed by water damage.

Evacuees seeking timeline on when they can return home

One Kalkarindji leader and Gurindji traditional owner, Rob Roy, said that after weeks in emergency accommodation, some in the Howard Springs centre were beginning to grow restless.

“I have a lot of people asking me, ‘when are we going back? How long are we staying?'” Mr Roy said.

“They’re homesick and they are worried about their cats and dogs.”

Mr Roy said he’s optimistic many people could be home in weeks rather than months.

However, he said he understood the scale of the clean-up effort ahead.

“There’s a lot of work there to do,” he said.

“Most of the houses that have been inundated still got no power, they have got to make sure the water is alright and safe to drink.

“Our general store, what I heard, is there’s no food in there and there’s got to be a big clean up there. They’re going to have to do that job before everybody goes back.”

Residents restricted from returning home

The Buntine Highway, which connects the three communities to other major highways, was reopened this week.

But Ms Manison warned residents against attempting to make the journey home.

“We’re trying to work to make sure that only people that should be in the community are in the community,” she said.

“We’re trying to coordinate that, we’re working through that, and we’re trying to restrict as much movement in there as possible.”

An emergency declaration remains in place, which allows the government to declare access to a community closed.

Authorities have said it’s likely Kalkarindji residents will be the first allowed to return to their community.

Media outlets have so far been denied permission to enter the communities to report on the damage or clean up effort.

Bunbidee/Pigeon Hole – E.coli

2013/14: Pigeon Hole Ecoli. 1 e.coli detection. 98% compliance

2015/16: Bunbidee E.coli 3 detections. 92% compliance

Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. While tests for thermotolerant coliforms can be simpler than for E. coli, E. coli is considered a superior indicator for detecting faecal contamination…” ADWG

Bunbidee/Pigeon Hole (Northern Territory) – Turbidity

2015/16: Bunbidee Turbidity 7.1NTU

Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment
process to address identified risks from Cryptosporidium and Giardia, it is essential
that filtration is optimised and consequently the target for the turbidity of water leaving
individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time
Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with
chlorine unless a higher value can be validated in a specific context.

Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the
consumer’s tap.

Bunbidee/Pigeon Hole (Northern Territory) Iron

2007/08: Bunbidee/Pigeon Hole Iron 0.41mg/L

Based on aesthetic considerations (precipitation of iron from solution and taste),
the concentration of iron in drinking water should not exceed 0.3 mg/L.
No health-based guideline value has been set for iron.

Iron has a taste threshold of about 0.3 mg/L in water, and becomes objectionable above 3 mg/L. High iron concentrations give water an undesirable rust-brown appearance and can cause staining of laundry and plumbing fittings, fouling of ion-exchange softeners, and blockages in irrigation systems. Growths of iron bacteria, which concentrate iron, may cause taste and odour problems and lead to pipe restrictions, blockages and corrosion. ADWG 2011

Bunbidee/Pigeon Hole (Northern Territory) Hardness

2007/08: Pigeon Hole Hardness 308mg/L

2009/10: Bunbidee Hardness 312mg/L

2010/11: Bunbidee Hardness 312mg/L

2013/14: Bunbidee Hardness 285mg/L

2015/16: Bunbidee Hardness 275mg/L

2016/17: Pigeon Hole Hardness 333mg/L

2021/22: Pigeon Hole Hardness 300mg/L (av.)

GUIDELINE

“To minimise undesirable build‑up of scale in hot water systems, total hardness (as calcium
carbonate) in drinking water should not exceed 200 mg/L.

Hard water requires more soap than soft water to obtain a lather. It can also cause scale to form on hot water pipes and fittings. Hardness is caused primarily by the presence of calcium and magnesium ions, although other cations such as strontium, iron, manganese and barium can also contribute.”